mercoledì 27 luglio 2011

A word cloud (or tag cloud) can be an handy tool when you need to highlight the most commonly cited words in a text using a quick visualization. Of course, you can use one of the several on-line services, such as wordle or tagxedo , very feature rich and with a nice GUI. Being an R enthusiast, I always wanted to produce this kind of images within R and now, thanks to the recently released Ian Fellows' wordcloud package, finally I can!
In order to test the package I retrieved the titles of the XKCD web comics included in my RXKCD package and produced a word cloud based on the titles' word frequencies calculated using the powerful tm package for text mining (I know, it is like killing a fly with a bazooka!).

As a third example, thanks to Jim's comment, I take advantage of Duncan Temple Lang's RNYTimes package to access user-generate content on the NY Times and produce a wordcloud of 'today' comments on articles.
Caveat: in order to use the RNYTimes package you need a API key from The New York Times which you can get by registering to the The New York Times Developer Network (free of charge) from here.

giovedì 14 luglio 2011

Being a big fan of XKCD and, of course, of the R programming language, I thought that a package which allows to display my favorite strips would something (useless) but cool!
So, mimicking the approach (and the code) of the fortunes package (thanks Achim Zeileis!), I created a simple package (names RXKCD) which allows the user to displays his favorite XKCD strip by selecting the specific number, randomly or simply displaying the current strip.
You can install the package using:

Update: The updated version of the package , which is available from CRAN (just type install.packages("RXKCD") ), allows the user to save the xkcd metadata database in a local directory (.Rconfig) and update it in order to have access to the latest XKCD info: see ?saveConfig and ?updateConfig.